Patents Assigned to TDK Semiconductor, Corp.
  • Patent number: 7102556
    Abstract: A method and apparatus for obtaining power computation parameters is presented. Accurate computation of power requires multiplying voltage and current at the same instant of time and integrating the results over time. The present invention provides a method of using a single Analog to Digital Converter to convert both voltage and current for all the phases of any electrical system and then digitally compensating for the phase error caused by the non-simultaneous sampling of the current and voltage signals. The compensating filter could be implemented as a simple interpolator, an all-pass filter, or a combination of both. A single multiplexer is used to select which signal is processed by the Analog to Digital Converter. By scheduling and converting the voltage and analog signals one at a time, potential for crosstalk is significantly reduced, power requirement is reduced, and die size requirement is reduced.
    Type: Grant
    Filed: March 18, 2005
    Date of Patent: September 5, 2006
    Assignee: TDK Semiconductor,Corp.
    Inventor: Bert White
  • Patent number: 7009603
    Abstract: A method and apparatus for driving light emitting polymer (PolyLED) displays is provided. Because PolyLED displays exhibit high capacitance characteristics, pre-charge current is injected to bring the diode up to near its operating current prior to enabling the diode. Thus, time and power is not wasted charging and discharging the high capacitance that is inherent in PolyLED displays and life of the diodes are prolonged because the diodes are not required to swing the full voltage range during each cycle. In addition, since older diodes need more voltage to produce the same current thus the same light intensity as newer diodes, an embodiment of the present invention adds an adaptive power generation system that actively monitors and adjusts power as necessary in order to generate constant amount of light (i.e., constant current) from all the diodes in the display.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: March 7, 2006
    Assignee: TDK Semiconductor, Corp.
    Inventors: Rich Page, Barry Thompson, Dave Mietus